Update to alsa situation

[Doug Sutherland]

Zach,

PCM means pulse code modulation (how audio is reproduced), 
but on the mixer it means sound output level. There is usually 
both a master volume and also separate PCM level, so it's not 
surprising at all that PCM will change your sound volume. To 
get any sound both have to be turned up. But you can set the 
PCM and leave it and use volume to adjust. The ALSA mixer 
is a bit complicated for sure. Way too many options in there.
I like simpler ones at least for regular non recording use.

  -- Doug